T-Mobile to filter VoIP

T-Mobile have been offering a "web and walk" service which includes unlimited data for a fixed monthly fee. They've now realised people can use that for VoIP too which means they lose revenues on voice calls (which is really how mobile networks make money).

So they've now decided to block VoIP access so people will have to use the phones to make voice calls.

It won't take long for someone to get round it, but it's probably the start of a trend with more companies blocking access to services they don't like.